Chemokines are chemotactic cytokines, of molecular weight 6-15 kDa, that are released by a wide variety of cells to attract and activate, among other cell types, monocytes, macrophages, T and B lymphocytes, eosinophils, basophils and neutrophils (reviewed in: Luster, New Eng. J. Med. 1998, 338, 436-445 and Rollins, Blood 1997, 90, 909-928). There are two major classes of chemokines, CXC and CC, depending on whether the first two cysteines in the amino acid sequence are separated by a single amino acid (CXC) or are adjacent (CC). The CXC chemokines, such as interleukin-8 (IL-8), neutrophil-activating protein-2 (NAP-2) and melanoma growth stimulatory activity protein (MGSA) are chemotactic primarily for neutrophils and T lymphocytes, whereas the CC chemokines, such as RANTES, MIP-1α, MIP-1β, the monocyte chemotactic proteins (MCP-1, MCP-2, MCP-3, MCP-4, and MCP-5) and the eotaxins (-1 and -2) are chemotactic for, among other cell types, macrophages, T lymphocytes, eosinophils, dendritic cells, and basophils. There also exist the chemokines lymphotactin-1, lymphotactin-2 (both C chemokines), and fractalkine (a CX3C chemokine) that do not fall into either of the major chemokine subfamilies.
The chemokines bind to specific cell-surface receptors belonging to the family of G-protein-coupled seven-transmembrane-domain proteins (reviewed in: Horuk, Trends Pharm. Sci. 1994, 15, 159-165) which are termed “chemokine receptors.” On binding their cognate ligands, chemokine receptors transduce an intracellular signal though the associated trimeric G proteins, resulting in, among other responses, a rapid increase in intracellular calcium concentration, changes in cell shape, increased expression of cellular adhesion molecules, degranulation, and promotion of cell migration. There are at least ten human chemokine receptors that bind or respond to CC chemokines with the following characteristic patterns (reviewed in Zlotnik et al., Immunity 2000, 12, 121): CCR-1 (or “CKR-1” or “CC-CKR-1”) [MIP-1α, MCP-3, MCP-4, RANTES](Neote et al., Cell 1993, 72, 415-425, and Luster, New Eng. J. Med. 1998, 338, 436-445); CCR-2A and CCR-2B (or “CKR-2A”/“CKR-2B” or “CC-CKR-2A”/“CC-CKR-2B”) [MCP-1, MCP-2, MCP-3, MCP-4, MCP-5](Charo et al., Proc. Natl. Acad. Sci. USA 1994, 91, 2752-2756, and Luster, New Eng. J. Med. 1998, 338, 436-445); CCR-3 (or “CKR-3” or “CC-CKR-3”) [eotaxin-1, eotaxin-2, RANTES, MCP-3, MCP-4](Combadiere et al., J. Biol. Chem. 1995, 270, 16491-16494, and Luster, New Eng. J. Med. 1998, 338, 436-445); CCR-4 (or “CKR-4” or “CC-CKR-4”) [TARC, MDC](Power et al., J. Biol. Chem. 1995, 270, 19495-19500, and Luster, New Eng. J. Med. 1998, 338, 436-445); CCR-5 (or “CKR-5” OR “CC-CKR-5”) [MIP-1α, RANTES, MIP-1β](Samson et al., Biochemistry 1996, 35, 3362-3367); CCR-6 (or “CKR-6” or “CC-CKR-6”) [LARC](Baba et al., J. Biol. Chem. 1997, 272, 14893-14898); CCR-7 (or “CKR-7” or “CC-CKR-7”) [ELC] (Yoshie et al., J. Leukoc. Biol. 1997, 62, 634-644); CCR-8 (or “CKR-8” or “CC-CKR-8”) [1-309](Napolitano et al., J. Immunol., 1996, 157, 2759-2763); CCR-10 (or “CKR-10” or “CC-CKR-10”) [MCP-1, MCP-3](Bonini et al., DNA Cell Biol. 1997, 16, 1249-1256); and CCR-11 [MCP-1, MCP-2, and MCP-4](Schweickart et al., J. Biol. Chem. 2000, 275, 9550).
In addition to the mammalian chemokine receptors, mammalian cytomegaloviruses, herpesviruses and poxviruses have been shown to express, in infected cells, proteins with the binding properties of chemokine receptors (reviewed in: Wells et al., Curr. Opin. Biotech. 1997, 8, 741-748). Human CC chemokines, such as RANTES and MCP-3, can cause rapid mobilization of calcium via these virally encoded receptors. Receptor expression may be permissive for infection by allowing for the subversion of normal immune system surveillance and response to infection. Additionally, human chemokine receptors, such as CXCR4, CCR2, CCR3, CCR5 and CCR8, can act as co-receptors for the infection of mammalian cells by microbes as with, for example, the human immunodeficiency viruses (HIV).
The chemokines and their cognate receptors have been implicated as being important mediators of inflammatory, infectious, and immunoregulatory disorders and diseases, including asthma and allergic diseases, as well as autoimmune pathologies such as rheumatoid arthritis and atherosclerosis (reviewed in: Carter, P. H., Curr. Opin. Chem. Biol. 2002, 6, 510; Trivedi et al., Ann. Reports Med. Chem. 2000, 35, 191; Saunders et al., Drug Disc. Today 1999, 4, 80; Premack et al., Nature Medicine 1996, 2, 1174). For example, the chemokine macrophage inflammatory protein-1 (MIP-1α) and its receptor CC Chemokine Receptor 1 (CCR-1) play a pivotal role in attracting leukocytes to sites of inflammation and in subsequently activating these cells. When the chemokine MIP-1α binds to CCR-1, it induces a rapid increase in intracellular calcium concentration, increased expression of cellular adhesion molecules, cellular degranulation, and the promotion of leukocyte migration.
In addition, demonstration of the chemotactic properties of MIP-1α in humans has been provided experimentally. Human subjects, when injected intradermally with MTP-1α, experienced a rapid and significant influx of leukocytes to the site of injection (Brummet, M. E., J. Immun. 2000, 164, 3392-3401).
The chemokines and their cognate receptors have been implicated as being important mediators of inflammatory, infectious, and immunoregulatory disorders and diseases, including asthma and allergic diseases; as well as autoimmune pathologies, such as rheumatoid arthritis and multiple sclerosis; and metabolic diseases, such as atherosclerosis and diabetes (reviewed in: Charo et al., New Eng. J. Med. 2006, 354, 610-621; Gao, Z. et al., Chem. Rev. 2003, 103, 3733; Carter, P. H., Curr. Opin. Chem. Biol. 2002, 6, 510; Trivedi et al., Ann. Reports Med. Chem. 2000, 35, 191; Saunders et al., Drug Disc. Today 1999, 4, 80; Premack et al., Nature Medicine 1996, 2, 1174). For example, the chemokine monocyte chemoattractant-1 (MCP-1) and its receptor CC Chemokine Receptor 2 (CCR-2) plays a pivotal role in attracting leukocytes to sites of inflammation and in subsequently activating these cells. When the chemokine MCP-1 binds to CCR-2, it induces a rapid increase in intracellular calcium concentration, increased expression of cellular adhesion molecules, and the promotion of leukocyte migration. Demonstration of the importance of the MCP-1/CCR-2 interaction has been provided by experiments with genetically modified mice. MCP-1−/− mice were unable to recruit monocytes into sites of inflammation after several different types of immune challenge (Lu, B. et al., J. Exp. Med. 1998, 187, 601). Likewise, CCR-2−/− mice were unable to recruit monocytes or produce interferon-γ when challenged with various exogenous agents; moreover, the leukocytes of CCR-2 null mice did not migrate in response to MCP-1 (Boring, L. et al., J. Clin. Invest. 1997, 100, 2552), thereby demonstrating the specificity of the MCP-1/CCR-2 interaction. Two other groups have independently reported equivalent results with different strains of CCR-2−/− mice (Kuziel, W. A. et al., Proc. Natl. Acad. Sci. USA 1997, 94, 12053, and Kurihara, T. et al., J. Exp. Med. 1997, 186, 1757). The viability and generally normal health of the MCP-1−/− and CCR-2−/− animals is noteworthy, in that disruption of the MCP-1/CCR-2 interaction does not induce physiological crisis. Taken together, these data lead one to the conclusion that molecules that block the actions of MCP-1/CCR2 would be useful in treating a number of inflammatory and autoimmune disorders (reviewed in: Feria, M. et al., Exp. Opin. Ther. Patents 2006, 16, 49; and Dawson, J. et al., Exp. Opin. Ther. Targets 2003, 7, 35). This hypothesis has now been validated in a number of different animal disease models, as described below.
It is known that MIP-1α is elevated in the synovial fluid and blood of patients with rheumatoid arthritis (Koch, A. et al., J. Clin. Invest. 1994, 93, 921-928). Moreover, several studies have demonstrated the potential therapeutic value of antagonism of the MIP-1α/CCR1 interaction in treating rheumatoid arthritis (Pease, J. E. et al., Expert Opin. Invest. Drugs 2005, 14, 785-796).
An antibody to MIP-1α was shown to ameliorate experimental autoimmune encepahlomytis (EAE), a model of multiple sclerosis, in mice (Karpus, W. J. et al., J. Immun. 1995, 5003-5010). Likewise, inflammatory disease symptoms could be controlled via direct administration of antibodies for MIP-1α to mice with collagen-induced arthritis (Lukacs, N. W. et al., J. Clin. Invest. 1995, 95, 2868-2876).
It is known that MCP-1 is upregulated in patients who develop bronchiolitis obliterans syndrome after lung transplantation (Reynaud-Gaubert, M. et al., J. Heart Lung Transplant., 2002, 21, 721-730; Belperio, B. et al., J. Clin. Invest. 2001, 108, 547-556). In a murine model of bronchiolitis obliterans syndrome, administration of an antibody to MCP-1 led to attenuation of airway obliteration; likewise, CCR2−/− mice were resistant to airway obliteration in this same model (Belperio, J. et al., J. Clin. Invest. 2001, 108, 547-556). These data suggest that antagonism of MCP-1/CCR2 may be beneficial in treating rejection of organs following transplantation. In addition, studies have shown that disruption of MCP-1/CCR2 axis was able to prolong the survival of islet transplant (Lee, I. et al., J. Immunol. 2003, 171, 6929; Abdi, R. et al., J. Immunol. 2004, 172, 767). In rat graft models, CCR2 and MCP-1 was shown to be upregulated in grafts that develop graft vasculopathy (Horiguchi, K. et al., J. Heart Lung Transplant. 2002, 21, 1090). In another study, anti-MCP-1 gene therapy attenuated graft vasculopathy (Saiura, A. et al., Arterioscler. Thromb. Vasc. Biol. 2004, 24, 1886). One study described inhibition of experimental vein graft neoinitimal formation by blockage of MCP-1 (Tatewaki, H. et al., J. Vasc. Surg. 2007, 45, 1236).
Other studies have demonstrated the potential therapeutic value of antagonism of the MCP-1/CCR2 interaction in treating asthma. Sequestration of MCP-1 with a neutralizing antibody in ovalbumin-challenged mice resulted in marked decrease in bronchial hyperresponsiveness and inflammation (Gonzalo, J-A. et al., J. Exp. Med. 1998, 188, 157). It proved possible to reduce allergic airway inflammation in Schistosoma mansoni egg-challenged mice through the administration of antibodies for MCP-1 (Lukacs, N. W. et al., J. immunol. 1997, 158, 4398). Consistent with this, MCP-1−/− mice displayed a reduced response to challenge with Schistosoma mansoni egg (Lu, B. et al., J. Exp. Med. 1998, 187, 601).
Other studies have demonstrated the potential therapeutic value of antagonism of the MCP-1/CCR2 interaction in treating kidney disease. Administration of antibodies for MCP-1 in a murine model of glomerularnephritis resulted in a marked decrease in glomerular crescent formation and deposition of type I collagen (Lloyd, C. M. et al., J. Exp. Med. 1997, 185, 1371). In addition, MCP-1−/− mice with induced nephrotoxic serum nephritis showed significantly less tubular damage than their MCP-1+/+counterparts (Tesch, G. H. et al., J. Clin. Invest. 1999, 103, 73).
Several studies have demonstrated the potential therapeutic value of antagonism of the MCP-1/CCR2 interaction in treating systemic lupus erythematosus. CCR2−/− mice exhibited prolonged survival and reduced renal disease relative to their WT counterparts in a murine model of systemic lupus erythematosus (Perez de Lema, G. et al. J. Am. Soc. Neph. 2005, 16, 3592). These data are consistent with the disease-modifying activity found in recent studies on genetic deletion of MCP-1 (Shimizu, S. et al. Rheumatology (Oxford) 2004, 43, 1121; Tesch, G. H. et al., J. Exp. Med. 1999, 190, 1813) or administration of a peptide antagonist of CCR2 (Hasegawa, H. et al. Arthritis & Rheumatism 2003, 48, 2555) in rodent models of lupus.
A remarkable 30-fold increase in CCR2+ lamina propria lymphocytes was observed in the small bowels from Crohn's patients relative to non-diseased ileum (Connor, S. J. et al., Gut 2004, 53, 1287). Also of note, there was an expansion in the subset of circulating CCR2+/CD14+/CD56+ monocytes in patients with active Crohn's disease relative to controls. Several rodent studies have demonstrated the potential therapeutic value of antagonism of the MCP-1/CCR2 interaction in treating Crohn's disease/colitis. CCR-2−/− mice were protected from the effects of dextran sodium sulfate-induced colitis (Andres, P. G. et al., J. Immunol. 2000, 164, 6303). Administration of a small molecule antagonist of CCR2, CCR5, and CXCR3 (murine binding affinities=24, 236, and 369 nM, respectively) also protected against dextran sodium sulfate-induced colitis (Tokuyama, H. et al., Int. Immunol. 2005, 17, 1023). Finally, MCP-1−/− mice showed substantially reduced colonic damage (both macroscopic and histological) in a hapten-induced model of colitis (Khan, W. I. et al., Am. J. Physiol. Gastrointest. Liver Physiol. 2006, 291, G803).
Two reports described the overexpression of MCP-1 in the intestinal epithelial cells and bowel mucosa of patients with inflammatory bowel disease (Reinecker, H. C. et al., Gastroenterology 1995, 108, 40, and Grimm, M. C. et al., J. Leukoc. Biol. 1996, 59, 804).
One study described the association of promoter polymorphism in the MCP-1 gene with scleroderma (systemic sclerosis) (Karrer, S. et al., J. Invest. Dermatol. 2005, 124, 92). In related models of tissue fibrosis, inhibition of CCR2/MCP-1 axis reduced fibrosis in skin (Yamamoto, T. et al., J. Invest. Dermatol. 2003, 121, 510; Ferreira, A. M. et al., J. Invest. Dermatol. 2006, 126, 1900), lung (Okuma, T. et al., J. Pathol. 2004, 204, 594; Gharaee-Kermani, M. et al., Cytokine 2003, 24, 266), kidney (Kitagawa, K. et al., Am. J. Pathol. 2004, 165, 237; Wada, T. et al., J. Am. Soc. Nephrol. 2004, 15, 940), heart (Hayashidani, S. et al., Circulation 2003, 108, 2134), and liver (Tsuruta, S. et al., Int. Mol. Med. 2004, 14, 837).
One study has demonstrated the potential therapeutic value of antagonism of the MCP-1/CCR2 interaction in treating alveolitis. When rats with IgA immune complex lung injury were treated intravenously with antibodies raised against rat MCP-1 (JE), the symptoms of alveolitis were partially alleviated (Jones, M. L. et al., J. Immunol. 1992, 149, 2147).
Several studies have shown the potential therapeutic value of antagonism of the MCP-1/CCR2 interaction in treating cancer (reviewed in: Craig, M. J. et al., Cancer Metastasis Rev. 2006, 25, 611; Conti, I., Seminars in Cancer Biology 2004, 14, 149; Giles, R., Curr. Cancer Drug Targets 2006, 6, 659). When immunodeficient mice bearing human breast carcinoma cells were treated with an anti-MCP-1 antibody, inhibition of lung micrometastases and increases in survival were observed (Salcedo, R. et al., Blood 2000, 96, 34-40). Using human clinical tumor specimens, CCR2 expression was associated with prostrate cancer progression (Lu, Y. et al., J. Cell. Biochem. 2007, 101, 676). In vitro, MCP-1 expression has been shown to mediate prostrate cancer cell growth and invasion (Lu, Y. et al., Prostate 2006, 66, 1311); furthermore, MCP-1 expressed by prostate cancer cells induced human bone marrow progenitors for bone resorption (Lu, Y. et al., Cancer Res. 2007, 67, 3646).
Multiple studies have described the potential therapeutic value of antagonism of the MCP-1/CCR2 interaction in treating restenosis. In humans, MCP-1 levels correlate directly with risk for restenosis (Cipollone, F. et al., Arterioscler. Thromb. Vasc. Biol. 2001, 21, 327). Mice deficient in CCR2 or in MCP-1 showed reductions in the intimal area and in the intima/media ratio (relative to wildtype littermates) after arterial injury (Roque, M. et al., Arterioscler. Thromb. Vasc. Biol. 2002, 22, 554; Schober, A. et al., Circ. Res. 2004, 95, 1125; Kim, W. J. et al., Biochem Biophys. Res. Commun. 2003, 310, 936). In mice, transfection of a dominant negative inhibitor of MCP-1 in the skeletal muscle (Egashira, K. et al., Circ. Res. 2002, 90, 1167) also reduced intimal hyperplasia after arterial injury. Blockade of CCR2 using a neutralizing antibody reduced neointimal hyperplasia after stenting in primates (Horvath, C. et al., Circ. Res. 2002, 90, 488).
Two reports describe the overexpression of MCP-1 rats with induced brain trauma (King, J. S. et al., J. Neuroimmunol. 1994, 56, 127, and Berman, J. W. et al., J. Immunol. 1996, 156, 3017). In addition, studies have shown that both CCR2−/− (Dimitrijevic, O. B. et al., Stroke 2007, 38, 1345) and MCP-1−/− mice (Hughes, P. M. et al., J. Cereb. Blood Flow Metab. 2002, 22, 308) are partially protected from ischemia/reperfusion injury.
It is known that monocytes/macrophages play an important role in the development of neuropathic pain (Liu, T. et al., Pain 2000, 86, 25). Consistent with this notion, a potential role for CCR2 in the treatment of both inflammatory and neuropathic pain has been described recently. CCR2−/− mice showed altered responses to inflammatory pain relative to their WT counterparts, including reduced pain behavior after intraplantar formalin injection and slightly reduced mechanical allodynia after intraplantar CFA injection (Abbadie, C. et al., Proc. Natl. Acad. Sci., USA 2003, 100, 7947). In addition, CCR2−/− mice did not display significant mechanical allodynia after sciatic nerve injury. Likewise, a small molecule CCR2 antagonist reduced mechanical allodynia to ˜80% ofpre-injury levels after oral administration (Abbadie, C. et al., WO 2004/110376).
One study described the critical role of MCP-1 in ischemic cardiomyopathy (Frangogiannis, N. G. et al., Circulation 2007, 115, 584). Another study described the attenuation of experimental heart failure following inhibition of MCP-1 (Hayashidani, S. et al., Circulation 2003, 108, 2134).
Other studies have provided evidence that MCP-1 is overexpressed in various disease states not mentioned above. These reports provide correlative evidence that MCP-1 antagonists could be useful therapeutics for such diseases. Another study has demonstrated the overexpression of MCP-1 in rodent cardiac allografts, suggesting a role for MCP-1 in the pathogenesis of transplant arteriosclerosis (Russell, M. E. et al., Proc. Natl. Acad. Sci. USA 1993, 90, 6086). The overexpression of MCP-1 has been noted in the lung endothelial cells of patients with idiopathic pulmonary fibrosis (Antoniades, H. N. et al., Proc. Natl. Acad. Sci. USA 1992, 89, 5371). Similarly, the overexpression of MCP-1 has been noted in the skin from patients with psoriasis (Deleuran, M. et al., J. Dermatol. Sci. 1996, 13, 228, and Gillitzer, R. et al., J. Invest. Dermatol. 1993, 101, 127); correlative findings with predominance of CCR2+ cells have also been reported (Vestergaard, C. et al., Acta Derm. Venerol. 2004, 84, 353). Finally, a recent report has shown that MCP-1 is overexpressed in the brains and cerebrospinal fluid of patients with HIV-1-associated dementia (Garzino-Demo, A., WO 99/46991).
In addition, CCR2 polymorphism has been shown to be associated with sarcoidosis at least in one subset of patients (Spagnolo, P. et al., Am. J. Respir. Crit. Care Med. 2003, 168, 1162).
It should also be noted that CCR-2 has been implicated as a co-receptor for some strains of HIV (Doranz, B. J. et al., Cell 1996, 85, 1149). It has also been determined that the use of CCR-2 as an HIV co-receptor can be correlated with disease progression (Connor, R. I. et al., J. Exp. Med. 1997, 185, 621). This finding is consistent with the recent finding that the presence of a CCR-2 mutant, CCR2-64I, is positively correlated with delayed onset of HIV in the human population (Smith, M. W. et al., Science 1997, 277, 959). Although MCP-1 has not been implicated in these processes, it may be that MCP-1 antagonists that act via binding to CCR-2 may have beneficial therapeutic effects in delaying the disease progression to AIDS in HIV-infected patients.
It should be noted that CCR2 is also the receptor for the human chemokines MCP-2, MCP-3, and MCP-4 (Luster, New Eng. Med. 1998, 338, 436-445). Since the new compounds of formula (I) described herein antagonize MCP-1 by binding to the CCR-2 receptor, it may be that these compounds of formula (I) are also effective antagonists of the actions of MCP-2, MCP-3, and MCP-4 that are mediated by CCR-2. Accordingly, when reference is made herein to “antagonism of MCP-1,” it is to be assumed that this is equivalent to “antagonism of chemokine stimulation of CCR-2.”